The scientific name for Hoelen is Poria cocos, which taxonomically belongs to the Class Eubasidiomycetes, the Subclass Hymenomycetidae, the Order Aphyllophorales, and the Family Polyporaceae. Poria cocos is sclerotia that grow mainly in pine roots and is called differently according to its internal colors; e.g., white Poria cocos with a white internal color and red Poria cocos with the a internal color. Since ancient times, it has been said that Poria cocos keeps the spleen healthy, is used as an ataractic agent, has the effects of stabilizing atopic dermatitis and body warming. Poria cocos is effective for the treatment of peptic ulcer, muscle spasm, thirst, dizziness, mental anxiety, and insomnia. As a herbal medicine, Poria cocos has efficacies on stamina, diuresis, sedation, etc., and is thus used for the treatment of kidney disease, cystitis, and urethritis. Additionally, Poria cocos is known to have an inhibitory effect against contact dermatitis.
A Poria cocos extract not only has the effect of alleviating gastric dysfunction but also has the effect of boosting stamina. In herbal medicine, Poria cocos extracts are classified into sedatives and diuretics. Additionally, Poria cocos extracts are used as an important component in the preparation of herbal medicine for energy recovery. According to recent studies and experiments with regard to the pharmacological efficacy of Poria cocos extracts, Poria cocos extracts have excellent efficacy against tumor and can improve the immunities of people suffering from chronic diseases and protect the stomach and intestines.
Sorghum bicolor L. Moench (Sorghum) is an annual plant belonging to the Family of Gramineae, which is one of the important grains, and mainly consumed as food in Korea. Sorghum contains a large amount of functional ingredients such as dietary fibers, phenolic compounds, etc., and the phenolic compounds consist of flavonoids, tannins, phenolic acids, etc., and most of these are known as flavonoids. Recently, many studies on the physiological functions of Sorghum have been reported. Sorghum extracts are known to exhibit strong antioxidant activity. Studies on the functionality of Sorghum include a study confirming antioxidant and antimicrobial activity after sequential solvent fractionation of 25 kinds of Sorghum by methanol extraction, a study measuring antioxidant activity of Sorghum anthocyanin, and reports on the phenolic components contained in Sorghum such as phenolic acid, flavonoid, tannin, etc.
Polymer materials are new materials widely used from applications in everyday life such as food, clothing, and shelter to advanced engineering fields such as electronics, life science, nanotechnology, environmental science, etc. Polymer processing is essential in the preparation of the final products needed by humans using these materials. At present, polymer production is higher than steel production in the world, as well as in Korea and Japan. As the amount of polymer being used increases, the method of molding polymer products also has an important role. The main point in forming polymers is the selection of materials and product design to ensure quality satisfaction at competitive prices, mold design, and operation of molding machines. In particular, quality satisfaction may be regarded as one not only satisfying the requirements of the state or size of a surface but also having the mechanical property, the orientation of the molecule, the minimum residual stress, and the appropriate structure inside the materials. Furthermore, in addition to the rheological characteristics, it is also important to know whether the resin is crystalline, amorphous, and what the maximum crystallinity is when selecting resins for forming polymer products. This is because the design of the formed product through the forming process must be matched to the forming process and the subject material, and thus a sufficient understanding of the polymer forming method may be essential in designing an optimal product.
Among polymer processes, films are available for all applications where textiles and paper are used, and are used in all industrial fields including aerospace and electronics, display, food packaging, and agriculture.
Examples of the methods for producing films using a polymer may include a solution casting method in which a high-viscosity polymer solution obtained by dissolving a polymer in a solvent is developed on a wide, smooth, non-adhesive surface and the solvent is volatilized to obtain a film; a melt processing method in which a polymer material is melt-processed by heating to a melting temperature or softening temperature or higher using heat and pressure to obtain a film; etc. The melt processing method is disadvantageous in that the method is not suitable for high-quality films such as optical functional films because the melt processing method cannot precisely control the thickness of films, thus generating fine lines (so-called “die lines”) on the films produced. In contrast, the solution casting method is advantageous in that the method can produce films with improved optical isotropy and thickness uniformity and fewer impurities compared to those prepared by the melt processing method. Additionally, the solution casting method is advantageous in that the method of use and installation equipment are very simple from the experimental aspect, and thus films with excellent properties can be easily produced according to the content of inorganic materials relative to various polymer materials.
Meanwhile, saponified polyvinyl alcohol has a relatively low viscosity compared to other polymers, is non-toxic, and has unique properties such as biodegradability. Additionally, saponified polyvinyl alcohol has excellent miscibility when blended with other polymers and is thus used for various purposes such as medical materials, packaging materials, release films, water-soluble films, etc. However, the methods of producing polyvinyl alcohol films reported so far have not been related to changing the surface of polyvinyl alcohol films, and in particular, there has been no report with regard to the method of controlling the surface roughness of polyvinyl alcohol films.
In this regard, for maximizing the specific surface area of polyvinyl alcohol films, the present inventors have made many efforts including controlling wrinkle formation or surface roughness of each polyvinyl alcohol film, and introducing the antioxidant effect or inhibitory effect against contact dermatitis of natural functional extracts such as a Poria cocos extract and Sorghum extract to the polyvinyl alcohol films in various ways. As a result, the present inventors have discovered that when a polyvinyl acetate film was prepared by the solution casting method using a natural functional extract and polyvinyl acetate as starting materials and then converted to polyvinyl alcohol containing the functional natural extract through a heterogeneous saponification process, the specific surface area of the film was improved while wrinkles were formed on the surface of the film and the film simultaneously contained the functional extract confirming the possibility of providing a functionality, thereby completing the present invention.